Abstract: AIM To determine the effects of the Glycoprotein M6B (GPM6B) gene on mesenchymal cells differentiating into smooth muscle cells. METHODS Infected sh-GPM6B cells were used as treatment group cells, and sh-Scramle cells were used as a control group. sh-GPM6B plasmids and tool plasmids were used to pack lentivirus in the 293T cell line. The virus was used to infect C3H10T1/2 cells into a sh-GPM6B stable transferring cell line. A fluorescent microscope was used to detect transfer efficiency and Western blot was used to detect interference efficiency. After incubation with TGF-β1 for 3 days in control cells and sh-GPM6B cells, the expression and transcription levels of smooth muscle cell specific marker proteins (SM-MHC and α-SMA) were detected by Western blot and q-PCR. RESULTS Compared with the sh-Scramble control group cells, expression levels of GPM6B in the sh-GPM6B treatment group cells infected with lenti-sh-GPM6B virus decreased to 40-70%. Compared with the sh-Scramble control group cells, the expression levels of SM-MHC and α-SMA proteins in the sh-GPM6B treatment group cells was significantly decreased (P<0.01). The transcription levels of SM-MHC and α-SMA mRNA were significantly decreased (P<0.01). CONCLUSION Knockdown of GPM6B represses mesenchymal cells differentiating into smooth muscle cells induced by TGF-β1.